scholarly journals 3D computational fluid dynamics modeling of temperature and humidity in a humidified greenhouse

2021 ◽  
Vol 13 (1) ◽  
pp. 17-31
Author(s):  
Cuauhtémoc Pérez-Vega ◽  
◽  
José Armando Ramírez-Arias ◽  
Irineo L. López-Cruz ◽  
Ramón Arteaga-Ramírez ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Natural Ventilation ◽  
Temporal Distribution ◽  
Cfd Modeling ◽  
Cfd Model ◽  
Dynamics Modeling ◽  
Temperature And Humidity ◽  
Humidity Measurements ◽  
Computational Fluid Dynamics Cfd

Introduction: Medium and low technology greenhouses use natural ventilation as a method of temperature and humidity control. However, at certain times of the year, this is insufficient to extract excess heat inside the greenhouse, so devices such as hydrophanes (humidifiers) have been implemented to reduce the temperature. It is necessary to know the behavior of temperature and humidity, since both factors influence the development of crops and, therefore, their yield. Objective: To develop a computational fluid dynamics (CFD) model of a naturally ventilated zenithal greenhouse equipped with hydrophanes to understand the spatial and temporal distribution of temperature and humidity inside the greenhouse. Methodology: The experiment was carried out in a greenhouse equipped with hydrophanes and grown with bell pepper. Temperature and humidity measurements were performed from March 7 to 25, 2014. The ANSYS Workbench program was used for the 3D CFD modeling. Results: The CFD model satisfactorily described the temperature and humidity distribution of the greenhouse, with an error of 0.11 to 3.43 °C for temperature, and 0.44 to 10.80 % for humidity. Limitations of the study: Numerical modeling using CFD is inadequate to model the temporality of the variables. Originality: There are few studies that model humidity behavior with CFD and the use of hydrophanes in Mexico. Conclusions: The CFD model allowed visualizing the distribution of temperature and air humidity inside the greenhouse.

Manufacturing and Computational Fluid Dynamics Modeling of a Patient-Specific Fistula Model

2017 ◽  
Author(s):  
Yang Liu ◽  
Yihao Zheng ◽  
John Pitre ◽  
William Weitzel ◽  
Joseph Bull ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Patient Specific ◽  
Cfd Model ◽  
Dynamics Modeling ◽  
Computational Fluid Dynamics Modeling ◽  
Computational Fluid Dynamics Cfd ◽  
Particle Imaging ◽  
Venous Wall ◽  
Good Agreement

Arteriovenous fistula is the joining of an artery to a vein to create vascular access for dialysis. The failure or maturation of fistula is affected by the vessel wall shear stress (WSS), which is difficult to measure in clinic. A computational fluid dynamics (CFD) model was built to estimate WSS of a patient-specific fistula model. To validate this model, a silicone phantom was manufactured and used to carry out a particle imaging velocimetry (PIV) experiment. The flow field from the PIV experiment shows a good agreement with the CFD model. From the CFD model, the highest WSS (40 Pa) happens near the anastomosis. WSS in the vein is larger than that in the artery. WSS on the outer venous wall is larger than that on the inner wall. The combined technique of additive manufacturing, silicone molding, and CFD is an effective tool to understand the maturation mechanism of a fistula.

Review of the Computational Fluid Dynamics Modeling of Fuel Cells

2005 ◽  
Vol 2 (4) ◽  
pp. 246-257 ◽  
Author(s):  
L. Ma ◽  
D. B. Ingham ◽  
M. Pourkashanian ◽  
E. Carcadea
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Fuel Cells ◽  
Proton Exchange Membrane ◽  
Proton Exchange ◽  
Cfd Modeling ◽  
Dynamics Modeling ◽  
Computational Fluid Dynamics Modeling ◽  
Computational Fluid Dynamics Cfd ◽  
Exchange Membrane

This paper presents a review of the current situation in the computational fluid dynamics (CFD) modeling of fuel cells and highlights the significant challenges that lie ahead in the development of a comprehensive CFD model for fuel cell applications. The paper focuses on the issues concerned with solid oxide fuel cells and proton exchange membrane fuel cells because these are the two most poplar and probably the most promising types of fuel cells for both stationary and transport applications. However, the general principles presented in this paper are applicable to all types of fuel cells.

scholarly journals Computational Fluid Dynamics Modeling of Liver Radioembolization: A Review

2021 ◽  
Author(s):  
Jorge Aramburu ◽  
Raúl Antón ◽  
Macarena Rodríguez-Fraile ◽  
Bruno Sangro ◽  
José Ignacio Bilbao
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Point Of View ◽  
Cfd Modeling ◽  
Dynamics Modeling ◽  
Cfd Simulations ◽  
Computational Fluid Dynamics Modeling ◽  
Cfd Models ◽  
Computational Fluid Dynamics Cfd ◽  
Intraarterial Therapy

AbstractYttrium-90 radioembolization (RE) is a widely used transcatheter intraarterial therapy for patients with unresectable liver cancer. In the last decade, computer simulations of hepatic artery hemodynamics during RE have been performed with the aim of better understanding and improving the therapy. In this review, we introduce the concept of computational fluid dynamics (CFD) modeling with a clinical perspective and we review the CFD models used to study RE from the fluid mechanics point of view. Finally, we show what CFD simulations have taught us about the hemodynamics during RE, the current capabilities of CFD simulations of RE, and we suggest some future perspectives.

scholarly journals ANALISIS DISTRIBUSI SUHU DAN KELEMBABAN UDARA DALAM RUMAH JAMUR (KUMBUNG) MENGGUNAKAN COMPUTATIONAL FLUID DYNAMICS (CFD)

2016 ◽  
Vol 36 (01) ◽  
pp. 64
Author(s):  
Anisum Anisum ◽  
Nursigit Bintoro ◽  
Sunarto Goenadi
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Natural Ventilation ◽  
Movement Pattern ◽  
Cfd Analysis ◽  
Treatment Variation ◽  
Air Movement ◽  
Temperature And Humidity ◽  
Computational Fluid Dynamics Cfd ◽  
Evaporative Cooler

One effort to optimize the temperature and humidity in the mushroom house during the dry season using evaporative cooler. This research was conducted two treatment variation which were assessed about distribution of temperature and humidity of air inside a mushroom house using Computational Fluid Dynamics (CFD) is the condition of building using natural ventilation and condition of building with water used evaporative cooler. Computational Fluid Dynamics (CFD) analysis was able to model the distributions of temperature and humidity, and air movement pattern inside of a mushroom house. The validation point of temperature distribution and humidity in the mushroom house has an error 0.70-2.62%. The results CFD analysis of temperature and humidity were able to reduced by about ±loC and ±5.1% for building with evaporative cooler used water. The indicated that buildings evaporative cooler used water able to reduced air temperature and increasing humidity in the mushroom houses.Keywords: Computational Fluid Dynamics (CFD), oyster, mushroom house,  evaporative cooler ABSTRAKSalah satu upaya untuk mengoptimalkan suhu dan kelembaban udara dalam rumah jamur pada musim kemarau dengan menggunakan evaporative cooler (pendingin penguap). Pada penelitian ini ada dua variasi perlakuan yang dikaji pendistribusian suhu dan kelembaban udara dalam rumah jamur dengan menggunakan Computational Fluid Dynamics (CFD), yaitu kondisi bangunan menggunakan ventilasi alamiah dan kondisi bangunan dengan pendingin penguap (evaporative cooler) menggunakan air. Analisis dengan Computational Fluid Dynamics (CFD) mampu memodelkan distribusi suhu dan kelembaban udara, serta pola pergerakan udara dalam rumah jamur. Nilai validasi distribusi suhu dan kelembaban udara dalam rumah jamur menunjukkan error 0,70 - 2,62%. Dari hasil analisis CFD suhu dan kelembaban udara mampu diturunkan sebesar ±1oC dan ±5,1% untuk bangunan dengan evaporative cooler menggunakan air. Hal ini menunjukkan bahwa bangunan dengan evaporative cooler menggunakan air mampu menurunkan suhu udara dan meningkatkan kelembaban udara dalam rumah jamur.Kata kunci: Computational Fluid Dynamics (CFD), rumah jamur (kumbung), evaporative cooler

scholarly journals Computational Fluid Dynamics Modeling of Rotating Annular VUV/UV Photoreactor for Water Treatment

Processes ◽  
2020 ◽  
Vol 9 (1) ◽  
pp. 79
Author(s):  
Minghan Luo ◽  
Wenjie Xu ◽  
Xiaorong Kang ◽  
Keqiang Ding ◽  
Taeseop Jeong
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Water Treatment ◽  
Cfd Modeling ◽  
Flow Mode ◽  
Oh Radicals ◽  
Dynamics Modeling ◽  
Rotational Movement ◽  
Contaminant Degradation ◽  
Wide Range

The ultraviolet photochemical degradation process is widely recognized as a low-cost, environmentally friendly, and sustainable technology for water treatment. This study integrated computational fluid dynamics (CFD) and a photoreactive kinetic model to investigate the effects of flow characteristics on the contaminant degradation performance of a rotating annular photoreactor with a vacuum-UV (VUV)/UV process performed in continuous flow mode. The results demonstrated that the introduced fluid remained in intensive rotational movement inside the reactor for a wide range of inflow rates, and the rotational movement was enhanced with increasing influent speed within the studied velocity range. The CFD modeling results were consistent with the experimental abatement of methylene blue (MB), although the model slightly overestimated MB degradation because it did not fully account for the consumption of OH radicals from byproducts generated in the MB decomposition processes. The OH radical generation and contaminant degradation efficiency of the VUV/UV process showed strong correlation with the mixing level in a photoreactor, which confirmed the promising potential of the developed rotating annular VUV reactor in water treatment.

Validation of a Computationally Efficient Computational Fluid Dynamics (CFD) Model for Industrial Bubble Column Bioreactors

2014 ◽  
Vol 53 (37) ◽  
pp. 14526-14543 ◽  
Author(s):  
Dale D. McClure ◽  
Hannah Norris ◽  
John M. Kavanagh ◽  
David F. Fletcher ◽  
Geoffrey W. Barton
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Bubble Column ◽  
Cfd Model ◽  
Computationally Efficient ◽  
Computational Fluid Dynamics Cfd

scholarly journals Journal Bearing: An Integrated CFD-Analytical Approach for the Estimation of the Trajectory and Equilibrium Position

2020 ◽  
Vol 10 (23) ◽  
pp. 8573
Author(s):  
Franco Concli
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Pressure Distribution ◽  
Equilibrium Position ◽  
Analytical Approach ◽  
Journal Bearing ◽  
Cfd Model ◽  
Cavitation Model ◽  
Computational Fluid Dynamics Cfd ◽  
The Mathematical Model

For decades, journal bearings have been designed based on the half-Sommerfeld equations. The semi-analytical solution of the conservation equations for mass and momentum leads to the pressure distribution along the journal. However, this approach admits negative values for the pressure, phenomenon without experimental evidence. To overcome this, negative values of the pressure are artificially substituted with the vaporization pressure. This hypothesis leads to reasonable results, even if for a deeper understanding of the physics behind the lubrication and the supporting effects, cavitation should be considered and included in the mathematical model. In a previous paper, the author has already shown the capability of computational fluid dynamics to accurately reproduce the experimental evidences including the Kunz cavitation model in the calculations. The computational fluid dynamics (CFD) results were compared in terms of pressure distribution with experimental data coming from different configurations. The CFD model was coupled with an analytical approach in order to calculate the equilibrium position and the trajectory of the journal. Specifically, the approach was used to study a bearing that was designed to operate within tight tolerances and speeds up to almost 30,000 rpm for operation in a gearbox.

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